Process of making 1-8-diaminonaphthalene-4-sulfonic acid.



UNITED STATES PATENT OFFICE.

JULIUS MCGENBURG, 0F LEVERKUSEN, NEAR COLOGNE, GERMANY, ASSIGNOR TOFARBENFAIBRIKEN VORM. FRIEDR. BAYER & (10., OF ELIBERFELD, GERMANY, A

CORPORATION OF GERMANY.

PROCESS OF MAKING 1-8-DIAMINONAPI-ITHALENE-l-SULFONIC ACID.

953,049. No Drawing.

To all whom "it may concern:

Be it known that I, JULIUS MocnNBURc, doctor of philosophy, chemist,citizen of the German Empire, residing at Leverkusen, near Cologne,Germany, have invented new and useful Improvements in New Processes forProducing 1-8-Diaminonaphthalene-4- Sulfonic Acid, of which thefollowing is a specification.

My invention relates to a new and valuable process for producing the1.8-diaminonaphthalenel-snlfonic acid.

This new process consists in submitting the acid sulfate of1.8-naphthylenediamin to the so-called baking process that is to say inheating in a suitable apparatus (preferably in 'vacuo) at temperaturesabove 100 C. the acidsulfate or mixtures of this naphthylenediamin withsulfuric acid capable of forming the acid sulfate.

In order to illustrate the new process more fully the following exampleis given, the parts being by weight: 158 parts of 1.8-diaminonaphthalene are added to a mixture which is being stirred of 255parts of a 96 per cent. sulfuric acid with 110 parts of water and thestirring is continued until the pulpy mass which is formed has changedSpecification of Letters Patent. Application filed August 26, 1909.Serial No. 514,817.

Patented Mar. 29, 1910.

into crumbs. These are then heated on plates in vacuo at about 155 C.for about 10 hours. The product is then dissolved in a dilute sodiumcarbonate solution and insoluble impurities are removed by filtration.On acidulating the filtrate the 1.8-naphthylenediaminl-sulfonic acidseparates in the shape of glistening flakes.

I claim 1. The process for producing 1.8-diaminonaphthalene-4-st1lfon1cacid, which process consists in heating the acid sulfate of 1.8-naphthylenediamin to temperatures above 100 C., substantially asdescribed.

2. The process for producing 1.8-diaminonaphthalenel-sulfonic acid,which process consists in heating a mixture of 1.S-naphthylencdiamin andsulfuric acid capable of forming the acid sulfate to temperatures above100 0., substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

JULIUS MOGENBURG. 1,. 8.]

Vitnesses OTTO Konic, WILLY KLEIN.

